1. Field of the Invention
The present invention relates to a working vehicle, for example, a tractor front loader backhoe (hereinafter, refer to as TLB).
2. Description of Background Art
Conventionally, in the TLB serving as the working vehicle, since various loads such as a compression, a tension, a deflection, a bending and the like are applied to a vehicle body frame constructing a traveling vehicle body in a complex manner at a time of traveling in a state in which a backhoe is installed to a rear portion of the traveling vehicle body or at a time of an excavating work by the backhoe, there is employed such a structure that a backhoe support frame for reinforcing is provided in a rear end portion of the vehicle body frame and the backhoe is installed to the backhoe support frame, for example, as described in Japanese Unexamined Patent Publication No. 6-32188.
In accordance with this structure, the backhoe support frame serves as a strength member complementing a rigidity of the vehicle body frame, and the load generated at a time of traveling in the backhoe installed state or at a time of the excavating work by the backhoe is dispersed to the vehicle body frame and the backhoe support frame. Accordingly, it is possible to improve a support strength as a whole of the traveling vehicle body.
In this case, a cast-iron heavy load such as an engine and a transmission case is coupled and fixed to the vehicle body frame mentioned above. The engine is arranged in a front portion of the vehicle body frame, and the transmission case is arranged in a rear portion of the vehicle body frame. Accordingly, the transmission case comes close to the backhoe support frame for reinforcing. Therefore, in the conventional structure mentioned above, since there is a risk that the load generated at a time of traveling in the backhoe installed state or at a time of the excavating work by the backhoe is propagated to the transmission case, it is necessary to thicken the transmission case for securing a strength. As a result, there is a problem that the mission case is made large in size and heavy and the vehicle body frame itself supporting the transmission case is made large in size and heavy, so that a manufacturing cost is increased.